


Let's solve this! Together!

by iori7se (jutsuzuban)



Category: IDOLiSH7 (Video Game)
Genre: Alternate Universe - Detectives, Detectives, Gen, I'm tweaking their characters a little to fit the AU, Iori and Mitsu will not be related this AU, Kaiketsu Mystery AU, M/M, Other Additional Tags to Be Added, POV Alternating, POV Third Person, Riku still has asthma, Slow Burn, Werewolves, characters to be added as they appear, their outfits are their Kaiketsu Mystery cards unless stated otherwise, title is a parody of the lyrics to Fly away!
Language: English
Status: In-Progress
Published: 2020-05-18
Updated: 2020-05-27
Packaged: 2021-03-03 03:40:25
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 4,515
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24258301
Author URL: https://archiveofourown.org/users/jutsuzuban/pseuds/iori7se
Summary: Ainana City, Japan, is a place full of life and love! Resident detective Nanase Riku would agree with that statement. However, with a new case given to him by a strange boy, the teenage detective starts to learn that that statement might have a dark side to it."You’re different from what I expected of a detective.""Well, I'm sorry to disappoint you."
Relationships: Izumi Iori/Nanase Riku, Izumi Mitsuki/Ousaka Sougo
Comments: 13
Kudos: 38





	1. First Meeting

**Author's Note:**

> First fic in the I7 fandom! Please treat me well.
> 
> Dedicated to my Nee-chan, Tori <3

Riku prided himself on solving problems and finding solutions where one may think there wouldn’t be one; it’s part of being a detective after all. Just today, he helped the local police figure out what caused a fire (thankfully not arson, it was the housecat knocking over a candle). Riku knew that not all cases were going to be that easy, but still, he was going to be a detective equivalent to Sherlock one day!

Except...maybe not right now, because there’s a boy who looks like Riku’s age sitting on the floor in front of the door to his apartment, and Riku does not recognize him at all nor know what he might want. The stranger turns his head towards the detective who’s standing at the end of the hall next to the elevator, and Riku immediately takes note of his messy dark hair, loose-fitting shirt and ripped jeans, and the odd collar around his neck. Sharp dark eyes looked into Riku’s red ones, and the young detective felt chills crawl up his spine. It wasn’t an aggressive stare, it was actually calm, but there was something wild that was hidden. An almost feral touch.

“Um, hello?” Riku says hesitantly as he approaches the stranger, who gets up to stand. Luckily, or unluckily, they were the same height, so Riku didn’t have to worry about height difference if the guy decided to attack him (detective work gets you places!). The boy continues to stare him down, and Riku is wondering how loud he could scream. 

“You’re different from what I expected of a detective,” the boy says bluntly, and Riku flinches from the emotionless tone the other uses. 

“Well I’m sorry to disappoint you.” Riku grumbles as he crosses his arms in front of his chest. “Now if you don’t mind me asking, what is a stranger doing outside my apartment? I’ll have you know my neighbors like me and will come out of their apartment if they hear me scream.” The boy stares at him unblinkingly, his expression one of exasperation, but he shuffles back away from Riku’s door.

“If you would, I’d like it if we could discuss this in private.” The boy picks at the hem of his shirt, rubbing the fabric between his thumb and pointer. Riku tilts his head, but decides that if this guy did prove to be a problem, he could restrain him. Humming softly, Riku gets closer to the door and the boy, smiling at him. 

“Okay, sure. Would you like a cup of tea?” Riku asks the boy, and he nods along, his messy hair bouncing with the motion. Riku laughs a little, then scrunches his nose as he feels a sneeze coming on. He ushers in the boy, directing him where to take off his shoes as Riku turns his head to sneeze into his elbow. 

“Oh, bless you,” the boy says as he pushes his sneakers up against the wall, and Riku opens his mouth to thank him, but he’s interrupted by a cough. Kicking off his shoes, Riku keeps his head turned away from his guest as he digs through his bookbag, his breath shaking and starting to wheeze. Thankfully, his inhaler was in a separate pocket away from the other contents of Riku’s bag, and the detective successfully administers the medicine.

“Sorry,” Riku turns to the boy with a reassuring smile as he clears his throat. He looks shocked, and his hands were up as if to help pat the ailing boy’s back. Riku waves that off and gestures to his small kitchen, pointing at one of the seats at the bar. ”Take a seat, I’ll make the tea.”

“Are...are you okay?” The boy asks as he slowly seats himself on the stool, and Riku laughs as he heats up water in a kettle. 

“Yea, I’m fine! I have asthma, if you couldn’t tell by the inhaler. I must have accidentally breathed in some dust or animal fur from outside.” Riku hums as he rummages through his cabinets to find the box of tea leaves the baker gifted him. “It’s not a real problem to me anymore, more annoying than anything.” _Ah, there’s the box!_

“I see,” the boy says warily, and Riku snaps his fingers as he cradles the box in one hand.

“Right! You probably know already, but my name is Nanase Riku. 18 years old.” He smiles at the boy, placing the box and his hands on the counter. “What’s your name?”

The boy hesitates, sucking in his lower lip to bite on it. Riku’s eyes zoom in on the sharper-than-normal canine, but looks back up into the other’s eyes, still smiling.

“Iori. I’m 17 years old.”

Riku raises a brow, tilting his chin down to peer at Iori over his glasses. “Just Iori?”

Iori nods. “I was told not to share my family name.”

Riku shrugs, and turns around to tend to the now whistling kettle. “That’s fine. Anyway, you mentioned earlier I’m not what you expected as a detective, so I assume you want me for my detective skills?”

“Ah, um--yes please.” Iori says, and Riku looks over at Iori who’s sporting a light blush. The redhead laughs, pouring the hot water over the tea leaves to let them steep in the cup. 

“I don’t mean it badly! So, what’s up?” Riku rests his elbows on the counter, resting his chin on his palm. Iori turns his head away, a frown on his face as his eyebrows scrunched together. 

“It’s my father,” Iori says slowly, mouth and jaw moving exaggeratedly as if his tongue was too heavy. “He’s been missing for a month now, and I can’t contact nor find him on my own.”

Riku frowns, his shoulders losing whatever tension was held left. Iori was still just a minor, not even having a driver’s license yet, and now his parent’s up and gone. The situation hits a little too close to home for Riku, but the detective busies himself with straining the tea to serve Iori.

“Ah, I see. Finding a missing person isn’t impossible, but it’s definitely time-consuming.” Riku slides over the cup of tea to Iori, sitting on the stool next to him. Iori leans away from Riku, and the redhead frowns but shrugs, taking a sip of tea.

“Thank you, and I’m well aware. I apologize, as I won’t be able to pay you right now, but I can do other things? I can help clean your apartment, if you want.” Iori fiddles with his cup, peering into the liquid as he blows over the top, looking like a man wary of their neighbor’s barking dog. Riku looks over the cute act with a smile. 

“Hmm, that’s fine with me. But because I won’t be paid, your case won’t be my first priority. I do have a job, you know.”

“I’m aware,” Iori huffs, finally taking a sip of tea. “I just...would like to find him.”

Riku’s eyes softened. “I get it, don’t worry. Now, it’s gotten pretty late--” a quick look at the clock face read 10:53 “--so why don’t you stay the night? Which reminds me to ask, how did you know where I live? I don’t recall ever stating anywhere where I live.”

Iori’s face flushes as he stares openly at Riku with wide eyes. _Cute_ , is the thought that goes through Riku’s mind because it truly was. Iori looked like a puppy who knew it had done something wrong, and Riku couldn’t help but laugh.

“No need to look like that! Look, you don’t have to tell me right now. Just stay the night? It doesn’t feel right sending you back home to an empty place.” _After all, I know how that feels._

Iori coughs and looks down at his tea. “Are you sure? Letting a person you don’t know stay over…”

“It’s fine! Besides, if you do something illegal, you’ll be caught within the week.” Riku winks at Iori with a grin, and gestures to Iori’s still full cup. “I’m done with my tea, so I’m going to go take a quick shower and change into my pajamas. You can shower after me, okay? You look like you could use it.”

Iori bristles at this, raising his shoulders like a petulant child. “Fine. Thanks, Nanase-san.”

Riku hums happily to himself as he stands up. “So formal! Well okay, Iori. I’ll set aside some clothes for you to use.”

With one last thanks from Iori, Riku bounces to his room, humming random melodies as he went. _I’ve never had guests stay the night! This is so exciting!_ Grinning as he hummed, Riku picked up a plain white T-shirt and red plaid pants with some underwear. Pausing in his humming, Riku muttered to himself as he picked out clothes for Iori. They looked the same build and height, but Iori could have longer legs than him...His baggy sweats will have to do. Removing a matching gray shirt off the hook, Riku folded them together and set them aside to hand over to Iori later.

He said he wouldn’t be making Iori’s case his first priority, but as Riku stepped into the shower, he knew he was lying to himself. He always took his cases a little too personally, and with this one too similar to his own life...Well, it was good to have drive, right?

**Notes for the Chapter:**

> I read a WikiArticle on how to make tea


	2. Coffee, Macarons, and Other Cute Things

**Summary for the Chapter:**

> “Hey hey, none of that! The coffee did nothing to you!”
> 
> “It offended my taste buds.”

**Notes for the Chapter:**

> Chapter starts in Iori's POV but switches to Riku's POV like halfway.
> 
> Also!! desc update!

Iori wasn’t sure what to think of the detective. On one hand, he hasn’t shown many detective-like qualities, but on the other hand, it’s not like Iori has presented him an opportunity to display whatever skills a detective should have. The only skill the redhead has displayed according to Iori is his incredible kindness.

Fingering the hem of his shirt, Iori eyes the cream-colored bag Nanase-san left lying on the ground next to his shoes. His nose twitched at the carelessness of it, and decides to leave his still-too-hot tea to pick up the bag and hang it on the coat rack standing next to the door. 

_Honestly, humans and their dirty habits!_ Iori’s nose twitches as he picks up the cream bag. The redhead’s scent--an unpleasant mix of potato chips and medicine--was strong on the bookbag, and Iori’s nose scrunched up as he places the strap onto a hook. _Ah, but he does have breathing problems, so that would explain the medicinal smell._

The shower was still running, which meant Nanase-san was still washing himself. Iori himself would prefer not to shower, but the redhead did offer, and it would be rude to decline. Besides, the thought of a warm shower sounded nice to him right now.

The squeak of a shower handle echoed in Iori’s ears. He tilted his head closer to the sound on instinct and faintly heard some shuffling. Iori rolls his shoulders and goes back over to the stool, sliding back onto it and picking up his tea. Without the detective around, Iori makes a face at the tea. It was so bland! He would have liked it better with some honey or sugar mixed in, but he thought it’d be rude to ask and impose even more than he already has, so Iori focuses on taking shallow sips of the tea in quick succession to rid himself of the tea.

“Ah, Iori!” Nanase-san walks out from the hallway, a fluffy white towel laying on his head. “You were just sitting there? You could’ve turned on the TV! I wouldn’t have minded.” In his hands were a set of gray clothes Iori assumed was for him. With the way the redhead was approaching and holding out the clothes, Iori would say he’s correct.

“I didn’t want to impose any more than I already had,” Iori says, and the redhead laughs, handing the younger boy the gray clothes.

“How cute!” Nanase-san giggles at the taken-aback flush that was no doubt on Iori’s face. “Anyway, here are your clothes! I uh, left a pair of underwear in the bathroom. You can put your clothes in the hamper! I’ll throw them in the washer down the hall when you’re done so they can dry in the morning.”

Iori coughs into his shoulder as he takes the clothes. “Thank you, Nanase-san. I appreciate what you’re doing for me.”

“It’s no problem! I’ve never had a guest stay overnight, so I guess you can say I’ve been wanting to have the chance to play host!” He scratches his cheeks as he laughs, tilting his head as his eyes forcibly closed due to his smile. “Ah, but that’s embarrassing to say to a stranger, isn’t it?”

Iori huffs as he darts his eyes away. _Cute_ . “I don’t think so. I’ve never been to another person’s place before.” _Not like I’ve had the chance at all to._

“So we’re both new at this!” Nanase-san’s smile softens as he looks at Iori. “Well, I won’t keep you. You stink!”

Iori rolls his eyes as he stares unimpressed at the redhead. “That’s not a very host-ly thing to say, is it?”

“Oh, just go shower!” His cheeks puff out like a squirrel as the redhead pouts, and Iori pushes down the urge to smile as he grips the clothes in his hands. 

“Thanks again, Nanase-san.”

“No problem. Oh, you can sleep on the couch! I’ll set it up for you while you shower. Do you want something to eat, too?”

“No thank you,” Iori says as he walks past the other to get to the bathroom. Just as he closes the door, he spots the redhead grab the cup of tea Iori left on the counter, towel precariously hanging off his head, and Iori barely realizes what he wants to say before his mouth opens. 

“You better use the towel on your head to dry your hair before it slips!” is what he says, and Iori squeaks as he slams the door closed. He hurriedly strips out of his clothes and hops into the shower, turning on the water to drown out any noise the redhead would make. 

_How embarrassing._

* * *

Iori woke up the next morning curled up on a small brown leather couch and a baby blue blanket over his body with a bitter smell invading his nose. His nose scrunches as he sniffles once, twice, then sneezes. 

“Oops! Did I wake you?” Iori tilts his head up to see red hair and ruby eyes peering over the back of the couch. A steaming mug was cupped in his hands, and Iori weakly glares at it.

“No, but the smell of your coffee did.” The boy brings the blanket up his face, burrowing his nose in the fabric in an attempt to get away from the bitter smell. He hears Nanase-san laugh and walk away, the bitter smell fading away as the redhead walks further away, and Iori pulls the blanket away from his face. 

“Sorry, sorry. So I guess you don’t want a cup?”

Iori’s ears wanted to perk up, but he firmly kept a hold on himself. _Father did seem to enjoy it, so maybe it isn’t that bad? He never let me try it._ “I’d like to give it a try.”

Nanase-san hums before taking out a small, red plastic cup, and he pours a little of the hot liquid into it. He drinks from his own mug, waiting for Iori to finish brushing his teeth with a borrowed toothbrush and come to the kitchen. Taking a seat at the same stool from yesterday, Iori looks into the cup, and his nose and eyebrows scrunch together at the smell. The redhead can’t help but laugh.

“You get used to the smell. Just give it a try.” Iori looks at the redhead with the same wariness he gave the drink, but eventually blows onto the liquid, making the redhead huff, but he didn’t say a word. Thinking the liquid was sufficiently cooled, Iori tilts the cup to block the view of his tongue poking out to dip into the liquid.

The reaction is immediate; Iori pulls the cup away from him and his face is twisted into one of disgust. Nanase-san laughs at him, and Iori hears a remark of how “cute” and “child-like” the action was, but he can’t bring himself to retort back as he focuses his attention on the bitter liquid and scowls at it.

“Hey hey, none of that! The coffee did nothing to you!” Nanase-san chastises him for scowling at the coffee. Iori refrains from pouting, but oh how he wants to.

“It offended my taste buds.”

Nanase-san rolls his eyes, but his eyes are smiling. He takes the cup, and then takes out a carton of milk and a little bag of sugar. He scoops up some sugar and splashes in some milk, handing the drink back to Iori as he puts the other two items back to their places. “There, it’ll taste better now.”

Iori takes the drink back skeptically. It _did_ look different, and smelled less strongly than before. He flicked his gaze back up at the redhead, who smiled encouragingly. Steeling himself, Iori closes his eyes and repeats the process of dipping his tongue into the liquid out of view from Nanase-san.

It _tasted_ different, too. It was sweeter, for one thing, and cooler thanks to the milk. Iori’s eyes opened up as he took in a real sip of the drink, and was elated to find the drink was much more to his tastes. If his tail was out, he was sure it’d be wagging to and fro from happiness. 

Nanase-san grins, puffing out his chest a little with pride. “Glad you like it! Now, do you want a new change of clothes, or would you rather wait for your clothes to finish drying?”

Iori sets the drink down, a light frown on his face. “Do you have somewhere you need to be?” Nanase-san turns his head to look at the clock, which Iori also takes a glance at. 9:20am. 

“Hmm, no, it’s still pretty early for me to show up at the station when there’s not a serious case happening, but I’d like to get breakfast at my friends’ bakery.”

“How long will my clothes take to dry?” Iori pinches his leg through the gray sweats he was wearing. He didn’t mind wearing them for a night, but going out in clothes not his own made his skin crawl. 

“Another 15 minutes, maybe?”

“Can you wait till then, please?”

Nanase-san smiles, and Iori is thankful the redhead is kind. “Sure, no problem.”

* * *

“Glasses?” Iori asks, and Riku hums. 

“Yea. I didn’t wear them yesterday because I forgot them at home, but luckily I had a pair at the station! I decided to leave them yesterday for the next time I accidentally forget my glasses at home.”

Iori’s eyebrows furrowed a little, and Riku smiled to himself at how often the other did that. “But don’t you need them to see? You could’ve gotten hurt on your way to your apartment.”

“My vision’s fine for the most part, I can get from the station to home anytime. I just can’t read too well or look at things close by without them.” Iori still has a look of displeasure on his face, so Riku waves his hand in front of Iori’s face as they walk side by side down the semi-busy sidewalk. 

“I mainly use them for reading, so it’s fine Iori! Jeez, you sound like my-” Riku cuts himself off there. “Ah, we’re here!” He stops Iori in front of a bakery with the name _‘Fonte Chocolat’_ written in swirly handwriting. _Good timing._

Not sparing a look at Iori, Riku pushes open the frosted glass door with a grin. “Mitsuki! Sougo-san! Good morning!” 

A man with white hair and soft purple eyes smiles at Riku. “Riku-kun, good morning! Is that a friend of yours?” Sougo’s eyes look past Riku’s shoulder to look at Iori, and Riku grins as he takes a step back and throws an arm around the other boy’s shoulders. 

“Yep! His name’s just Iori.” Riku grins, and presses his glasses up his nose. “Where’s Mitsuki?”

“Right here!” A peach-colored head of hair pokes out from the door to the kitchen, and Mitsuki shoots a grin. “Hey there Riku! You’re here pretty late. Missed the morning rush!” His smile turns into a smirk. “Though you don’t need to care about that, do you? Working late morning shifts like yourself, aren’t you lucky?”

Riku laughs as he flushes. “The bakery wouldn’t be the same without you, Mitsuki!” As Mitsuki steps out of the kitchen with exclaims of how sweet a boy Riku was, the detective turns towards his companion. “These two are Osaka Mitsuki and Osaka Sougo! They’re two of my best friends!”

“Ah! Did you hear that Sougo? We’re his best friends!” Mitsuki grins at the taller man, and Sougo smiles back. “Yes, we’re two of them.”

“Osaka...both of them?” Iori’s brows furrow, and Riku purses his lips together to keep from smiling. “Are they brothers?”

Riku loses control, releasing his hold on Iori’s shoulders to clap both his hands over his mouth to keep down his laughter. Mitsuki himself is bent over the counter, clenching a fist on the apron he was wearing. Sougo too was amused at the whole situation, a smile dancing on his lips.

“Iori-kun, Mitsuki and I are married.” “...Eh?”

“Just get me my usual strawberry pastry, please,” Riku says in-between laughter. Iori’s face is so red and his mouth is flapping open and closed like a fish as he apologizes. Mitsuki waves him off as he calms down, breaking out into short giggle fits. “Coming right up.”

“Do you want anything, Iori?” Riku turns his head to look at the other boy, only to blink in surprise as he notices Iori had moved close to the bakery’s displays and had his face close to one. His eyes were wide with amazement as he lasered onto some dark blue macarons with yellow star candies decorating it. Riku had the mental image of perky ears and a wagging tail on Iori from how excited and happy he looked entering his mind, and laughed to himself.

“Ring me up for some of those macarons too, please, Sougo-san.” Iori whips his head towards Riku, eyes still wide but with surprise flooding them now. Distantly, Riku thinks this is how Iori should look--like a wide-eyed kid instead of the serious persona he keeps up.

“Nanase-san!” Iori’s mouth twists into a frown even though his eyes were still sparkling with diluted happiness. “You- I don’t need them.”

“It’s my treat! Besides, you don’t have money, right? Plus you didn’t have anything back at my place, only coffee!” Riku crosses his arms, and turns his attention back to the older men. “How much is it?”

“300 yen.” Sougo smiles at Riku’s confused look. He winks as he says, “The macarons will be on the house.”

“E-eh? No, I can’t accept that,” Iori flusters, straightening up from squatting in front of the display. “I can’t pay you, but I can do menial work like mop the floors or clean dishes.”

Mitsuki frowns as he slips a strawberry pastry into a paper bag for Riku. “No way! You’re Riku’s friend, and you seem like a nice kid. At least, you’re a kid with good taste.” The baker grins as he gently sets six of his hand-crafted macarons down into a box. “Just take care of Riku for Sougo and I, yea? We worry about the kid!”

“Oi!” Riku pouts as his hands go to open his bookbag. “I’ll have you know that _I’m_ older than Iori! So I should be watching him!”

“You can both watch each other,” Sougo says smoothly as he rings up Riku’s order. Riku’s pout stays on though, until he snaps his fingers.

“Okay, if we can’t pay you, then can you get me another strawberry pastry? I’ll bring it to Yaotome-san!” Sougo kindly raises the price as Riku takes out 600 yen from his wallet, eagerly taking the now two paper bags from Mitsuki. Iori takes a white box imprinted with the bakery’s name on top carefully with both hands as Mitsuki hands it out to him, and bows while saying his thanks.

Sougo laughs softly as his face pinkens with embarrassment. “No need for that, Iori-kun. It’s our treat, so don’t worry about it.” Mitsuki agrees with Sougo, and the couple bid the boys goodbye as they exit the shop, treats in hand. 

“They’re nice, right?” Riku grins at Iori as he holds the strawberry pastries to his chest. Iori smiles softly as he opens his box and looks down at the macarons, the soft yellow stars bright against the shiny dark blue of the cookie. 

“Yea, they are nice.”

Riku grins, and looks into the box. His eyes blink once in surprise, but his grin widens. “Super nice! Mitsuki gave you an extra one!”

“Really!?”

* * *

The pair arrive at the station, and Riku smiles as he greets everyone: Yamato-san lazing on the couch, Yaotome-san reading the newspaper next to the green-haired man, Tsunashi-san standing at the water cooler to get a drink. Riku notes that Tsumugi wasn’t in the common area, so she must be helping her dad with paperwork.

“Morning Yamato-san, Yaotome-san, Tsunashi-san!” Riku makes sure to turn his head and body towards each person so Iori could see who was who. “Yaotome-san, I brought you a pastry from Mitsuki and Sougo-san’s bakery!”

“Ah, thanks Nanase. I was thinking about it just now,” Yaotome says with a smile. Riku teases him (“the pastry or strawberries?”) as he hands the silver-haired man his pastry. Yamato waves a hand at Riku from his relaxed position on the couch.

“Yo, Riku, who’s the kid?”

Riku grins as he does a half twirl and holds his arms out to introduce Iori. “This is Iori! He’s a client of mine as of today! I’m gonna take him into my office, so knock if it’s urgent!”

Yamato makes an affirming noise as Tsunashi turns to smile at Iori, who was twiddling his thumbs, the picture of nervousness. “Hello there, Iori-kun. You don’t have to be nervous around Riku-kun, he’s a good kid!” Iori nods hesitantly, like a shy kid who’s talking to someone they don’t know. Riku grins inwardly, _So Iori can be cute like this too._

“Yep! No need to be shy!” Riku goes along with Tsunashi’s line. “My office is this way, Iori!” The detective leads the boy to a door past the common area, and opens the door to usher Iori in. Before he completely closes the door, Riku hears Yamato remark how familiarly Riku referred to Iori, but Yaotome says back, “It’s Nanase, what else would you expect?”

Smiling, Riku turns to Iori, and strides over to his desk, where he gestures for Iori to take a seat. Settling down into the armchair (with wheels!), Riku tilts his head and lets his smile soften into a more composed, serene one. 

“So, tell me the details of your father’s disappearance.”

**Notes for the Chapter:**

> I usually refrain from using double punctuation marks in my fics but sometimes they're the only way to properly communicate things u-u


End file.
